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California Regional Water Quality Control Board <br /> Central Valley Region <br /> Robert Schneider,Chair <br /> Alan C.Lloyd,Ph.D. Arnold <br /> Agency Secreraiy Sacramento Main Office Schwarzenegger <br /> 11020 Sun Center Drive#200,Rancho Cordova,California 95670-6114 Governor <br /> Phone(916)464-3291 •FAX(916)464-4645 - <br /> http://www.wateT-boards.ca.gov/centralvalley <br /> 6 October 2005 OCT s <br /> ENvIR0�1w,'� 1 � i',�a1'� <br /> Mr. Jim Levy <br /> Union Pacific Railroad Company <br /> 9451 Atkinson Street, Suite 100 <br /> Roseville, CA 95747 <br /> 2004./2005 ANNUAL MONITORING REPORT, UNION PACIFIC RAILROAD COMPANY, TRACY <br /> MAINTENANCE FACILITY, SAN JOAQUIN COUNTY <br /> Central Valley Regional Water Quality Control Board staff(Regional Board staff)has reviewed the <br /> 2004/2005 Annual Monitoring Report(Annual Report) for the Union Pacific Railroad Company's Tracy <br /> Maintenance Facility(UPRC Site) received on 3 May 2005. Regional Board staff comments on the <br /> Annual Report are provided below. In addition, Regional Board staff reviewed several supporting <br /> documents to the Annual Report and additional comments on the status of source area remediation are <br /> provided at the end of this letter. <br /> Comments on 2004/2005 Annual Report <br /> 1. Regional Board staff is pleased with the progress made in remediating the UPRC site. The total <br /> extractable petroleum hydrocarbons (TEPH) and halogenated volatile organic compounds (HVOC) <br /> plumes appear to have stabilized within the boundaries of the UPRC site and concentrations appear <br /> to be declining in most on-site monitoring wells. However, concentrations of TEPH and HVOCs <br /> still exceed cleanup levels specified in Cleanup and Abatement Order(CAO)No. 92-707 and are <br /> unlikely to decrease below these cleanup levels within the next 2 years. Regional Board staff does <br /> not concur with the recommendation to assess this site for No Further Action (NFA) in 2006 unless <br /> concentrations of HVOCs are below site cleanup levels and the TEPH plume continues to decrease <br /> in aerial extent. <br /> 2. Regional Board staff concurs with shutting down the margin extraction system at this time, but no <br /> extraction wells should be decommissioned. Furthermore, the monitoring frequencies of several <br /> wells along the margin of the plumes may need to be increased and a contingency plan should be <br /> prepared to restart the margin extraction well system if future monitoring data indicates the TEPH or <br /> HVOC plumes are migrating toward the down gradient property line. <br /> 3. Assuming the TEPH plume continues to shrink, achievement of HVOC cleanup levels is the key to <br /> obtaining our concurrence on NFA. The total extent of the HVOCs plume appears to be limited to <br /> California Environmental Protection Agency <br /> �a Recycled Paper <br />